Tire sealant dispensing apparatus

ABSTRACT

A tire-sealing apparatus for injecting a sealing composition into a vehicle tire either as a prophylactic or for sealing an existing leak is in the form of a pressurizeable container for a flowable sealant compound. An inlet is provided for introducing compressed gas into the container to pressurize its contents. An outlet line is also provided to deliver the sealant into a tire, the pressurized gas acting on contents of the container and providing the motive force for the delivery. A dip tube extends into the compound and is coupled to a one-way valve to provide a controlled flow of the compound from the container into the tire while preventing back pressure of the tire from either delivering air or compound back into the container. A passageway between the outlet tube and an interior of the container is provided to allow a flow of compressed gas within the container into the outlet tube along with the sealant.

The present invention relates to an apparatus and method for dispensing a measured amount of a fluid under pressure and in particular to an apparatus for dispensing tire sealant into a vehicle tire. Applicants claim the benefit of U.S. Provisional Application 60/983,423 filed Oct. 29, 2007, the contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

Vehicle tire repair technology is well developed. In one well known aspect, a tire, such as an automobile or truck tire, damaged and deflated by a puncture, such as by a nail, is demounted from the vehicle and the puncture point located. An elastomeric plug is inserted into the puncture hole creating an airtight seal. The tire can then be re-inflated and re-installed on the vehicle. Such a methodology has the deficiencies that the tire must be removed from the vehicle and the location of the puncture found. When the puncture-causing object no longer is in the tire some degree of skill and care is required to locate the entry point. In addition, the proper choice and insertion of a plug normally requires a skilled automotive technician.

A second methodology for the repair of such punctures incorporates the injection of a sealant compound into the tire interior under pressure. The sealant material coats the inside of the tire and seals the leak.

In a version of the foregoing, a liquid sealant is injected into the tire, with the inflation valve core removed. Rotation of the tire causes the sealant to spread over the inner surface of the tread area, sealing the leak. Such compounds may be placed in the tire before a leak occurs, the liquid remaining in a flowable state until a puncture occurs, at which time the air pressure in the tire forces the composition into the puncture hole and seals the leak.

Injectable sealant systems typically are sold in aerosol containers, which are connected to the tire valve by a short tube. The quantity of sealant in the can is often limited, and there is a limited amount of compressed gas in the container to drive the fluid. Often such containers do not have sufficient contents to re-inflate a punctured tire sufficiently to allow the tire to be driven on safely; the partially-inflated tire exposes the tire rim to increased damage from potholes or other road hazards. They also do not prevent future puncture leaks.

Others of such sealant systems are provided in a squeezable container, whereby the user collapses the container to inject the contents. These systems require the valve core of the tire to be removed and the tire deflated, as the viscous sealant used would clog the valve core, and any pressure in the tire would prevent the user from squeezing the bottle to force the sealant into the tire. After use the valve core must be reinserted into the valve and the tire re-inflated.

BRIEF DESCRIPTION OF THE INVENTION

It is a purpose of the present invention to provide a tire repair and inflation apparatus which may be used to inject a tire sealant of a chosen viscosity into a tire both to repair tire punctures after they occur, as well as to provide preventative to the loss of air on future puncture occurrence without removal of a tire valve core. In accordance with the foregoing, the present invention comprises a pressurizable container in which a sealant liquid composition is located. The container is provided with an outlet line to connect the container to the valve stem of a tire to be treated, and an inlet port connectable to a source of compressed gas, such as an air compressor. In a preferred embodiment the container includes a valve system such that the compressed gas entering the container pressurizes the container to drive the sealant liquid into the tire while at the same time feeding amounts of the pressurizing gas into the tire, assisting in the delivery and dispersion of the liquid within the tire. Backflow prevention from the tire into the container is also provided. The apparatus may preferably be used without removal of the tire valve stem core as it allows a variety of sealants, having a wide range of viscosities, to pass through the valve and not block the valve stem core, and thus can be used without full deflation of the tire. Both sealant and air can be delivered simultaneously; the tire need not be reconnected to a separate inflation device.

BRIEF DESCRIPTION OF THE DRAWINGS

A fuller understanding of the present invention will be achieved upon consideration of the following detail description of a preferred but nonetheless illustrative embodiment of the invention when considered in conjunction with the annexed drawings, wherein:

FIG. 1 is a perspective view, not to scale, of the present invention in use;

FIG. 2 is a sectional view of the cover for the container of the invention;

FIG. 3 is an exploded view of the dip tube of the invention and associated valve components to be mounted to the cover;

FIG. 4 is a detail view of the dip tube valve body showing the mushroom-shape seal to prevent tire backflow; and

FIG. 5 is a sectional view of the cap taken along line 5-5 in FIG. 3 depicting how an outlet line seal is created.

DETAILED DESCRIPTION OF THE INVENTION

With initial reference to FIG. 1, the present invention comprises a container assembly 10 for a quantity of sealant fluid 12 intended to be injected into tire 14 to either seal a pre-existing puncture hole or to serve as a prophylactic against loss of air from the tire through a subsequent puncture. The sealant may be of a type generally known in the trade, including vinyl or cellulose-based types, with binders and clotting agents of the general type known in the art. The fluid contents 12 of the container assembly are directed upward through dip tube 16 and delivered to the interior of the tire through outlet tube 18, which terminates in a connector 20 of known construction that attaches to the inflation valve stem of the tire. The air space 22 above the sealant fluid 12 in the container assembly is pressurized to drive the fluid through the dip tube and outlet tube into the tire. The internal container pressure is developed by a suitable source of compressed gas, such as air compressor 24, whose outlet is coupled to the interior of the container assembly by hose 26, which may be part of the compressor assembly. The compressor 24 may be, for example, a compressor driven by a 12-volt direct current source, allowing the compressor to be a unit connectable to an automobile battery, thus allowing portable use of the apparatus.

With further reference to FIGS. 2-4, container assembly 10 includes container 28 which may, for example, be of an appropriate metal or plastic composition with a wall thickness and strength sufficient to accommodate pressurization by the compressor 24 or otherwise, and cap or cover 30. An acceptable volume for the container may be on the order of 20 ounces, accommodating a 16-ounce fill of sealant fluid, but may be larger or smaller depending on the size of the tire with which it is intended to be used. Cap 30 is threaded onto the open neck 32 of the container, rubber washer 34 providing an airtight seal therebetween. Cap 30 may be provided with a circumferential skirt 36 surrounding and protecting the cap-container interface.

Threaded port 38, molded into the cap, provides an entryway into inlet bore 40 in the cap which delivers the compressed air into the interior volume of container 28. The exterior of port 38 may be threaded to accept a mating coupling 72 on inlet tube 26. While washer 34 provides a seal between the container and cap, the seal may exist primarily about the washer's outer circumference, where it is compressed between the upper edge of the container's neck and the cap. The inlet air in inlet passageway 40 may pass by the inner circumference of the washer into the threaded neck-receiving portion of the cap, allowing the delivered air to enter into the container.

Cap 30 also includes integral outlet port 42 which connects to outlet tube 18 to deliver sealant fluid to the tire. As shown in the figures, the port 42 may have a barb-like flange portion 74 to sealingly engage the outlet tube 18, or may be alternatively provided with a coupling to which the outlet tube may be connected. Outlet port 42 provides a termination for outlet passageway 44 within the cap, which leads from valve body chamber 46 in the cap.

As shown in FIGS. 2 and 4, valve body chamber 46 supports valve spring 48 and valve seal 50, and is closed by valve chamber cover 52, which may be sonically welded or otherwise affixed to the lower end of the cap and extends downwardly, and provides a connection point for the dip tube 16.

As may be seen, valve spring 48 biases valve seal 50 downward to seat against inlet opening 54 of the thru-passageway 78 of valve chamber cover 52, serving as the continuation of the valve chamber 46. Valve spring 48 may be of minimal biasing force, sufficient only to close the inlet opening 54 in the absence of above-atmospheric pressure in the bottle. Thus, the valve assembly provides a one-way check valve function, preventing air from the tire from backfilling into the container, but allowing the pressurized contents of the container to flow into the tire, so long as the created container pressure exceeds that of the tire. As may be seen in FIG. 4, valve chamber cover 52 includes a transverse orifice 56 providing a passageway between the container interior, above the level of the sealant fluid 12, and passageway 78 and valve body chamber 46. Accordingly, when the container is pressurized both sealant 12 and air are delivered to the tire. Due to turbulence and mixing effects within the passageway and valve body chamber, a “bubbling” or “pulsing” blend of air and sealant is developed, assisting in transporting the sealant through the outlet tube and into the tire, through the valve stem core, if present, without clogging.

Dip tube 16 is connected to neck portion 58 of the valve cover with a friction fit, the barbs 76 on the exterior neck portion holding the dip tube securely. The dip tube extends downwardly into the sealant fluid, thus providing an exit path for the pressurized sealant and, after the sealant is fully drawn out, for additional compressed air, allowing the tire to be pressurized as desired. Because of the small size of orifice 56 (such as 0.040″ as compared to a 0.088″ diameter of the thru-passageway 78) a small amount of air is injected while the sealant is being delivered.

With reference to FIGS. 3 and 5, cap 30 includes a generally planar ledge 60 positioned with its lower surface 62 spaced from and parallel to the upper surface 64 of the cover. As shown, the space 68 therebetween provides a storage space for outlet tube 18, which may be wrapped about the central stem portion 66 through which inlet bore 40 extends and which supports the ledge over the cap upper surface 64. In addition to allowing the tube to be conveniently stored with the container, the wrapping forms a sharp bend or kink point 68 that pinches the tube closed. This seals the outlet line and prevents travel of the sealant fluid 12 into the outlet tube 18 if the container is squeezed or upset. The upper surface of the cover and lower surface 62 of the planar edge 60 may be provided with a pair of complementary raised portions 70 as depicted in FIG. 5. The outlet tube 18 is of a length that, when gently stretched, the rearwardly-directed edge 80 of a portion of the coupling 20 is positioned to bear against a side of the raised portion, the tension developed in the slightly-stretched tube holding the coupling against the raised potion to maintain the tube in the coiled configuration while maintaining the kink 68.

In use, the compressor's hose 26 is extended and its connector or chuck attached to port 38, and the outlet tube 18 connected to the tire. The compressor is turned on, sending compressed air into the container interior. The check valve opens due to the direction and pressure of the sealant fluid being forced up the dip tube, and the sealant is injected into the tire. At the same time, orifice 56 allows a quantity of the compressed air in the container to mix with the fluid passing through the valve body 52, assisting in transporting the fluid and disbursing it within the tire. When the fluid is fully injected the compressor can continue to be operated to further inflate the tire as needed. When sufficient inflation has occurred the compressor is shut down. Pressure in the outlet line 18 closes down the check valve, preventing tire air loss while the apparatus remains connected to the tire. The outlet tube is then removed from the tire. Because the container 28 is removably connected to the cap 30, the entire apparatus does not have to be disposed of after use. A replacement container, with a new charge of sealant fluid, can be installed on the cap whenever needed. 

1. A tire sealing apparatus, comprising: a pressurizable container for accepting a quantity of flowable sealant; inlet means for introducing compressed gas into the container; outlet means for delivering the sealant compound into a tire, the outlet means including an outlet tube; and an orifice between the outlet means and an interior of the container above a level of sealant in the container to direct a flow of compressed gas within the container into the outlet tube in association with a flow of the sealant from the container.
 2. The apparatus of claim 1, further comprising a one-way valve associated with the outlet tube with a flow direction towards the tire and away from the sealant in the container.
 3. The apparatus of claim 2, wherein the one-way valve comprises a spring and a valve element biased by the spring.
 4. The apparatus of claim 3, wherein the valve means is located in a removable cover for the container.
 5. The apparatus of claim 3 wherein the valve means further includes a valve cover extending downwardly from the cover, the valve cover connecting with a dip tube for delivering the sealant to the outlet tube.
 6. The apparatus of claim 1, further comprising means for providing the compressed gas to the inlet means.
 7. The apparatus of claim 6 wherein the gas providing means is a compressor.
 8. The apparatus of claim 4 wherein the outlet means includes a coupling for the outlet tube formed integrally with the cover.
 9. The apparatus of claim 4 wherein the inlet means includes a tubing coupling formed integrally with the cover.
 10. The apparatus of claim 4 wherein the cover includes means for storing a quantity of tubing.
 11. The apparatus of claim 10 wherein the quantity of tubing is at least a portion of the outlet tube.
 12. The apparatus of claim 10 wherein the storing means comprise a pair of parallel surfaces spaced to accommodate tubing coiled therebetween.
 13. The apparatus of claim 12 wherein one of the parallel surfaces is a top surface of the cover.
 14. The apparatus of claim 12 further including raised surfaces portions on the parallel surfaces to engage the coiled tubing, the coiled tubing being the outlet tube, the outlet tube including a coupling at a distal end, the raised surface portions being adapted to engage the distal end coupling.
 15. The apparatus of claim 13 wherein the coiled tubing is a portion of the outlet tube, the outlet tube including a coupling at a distal end, the raised surface portions being adapted to engage the distal end coupling.
 16. The apparatus of claim 10 further comprising means for selectively sealing the quantity of tubing.
 17. The apparatus of claim 16, wherein the means for storing a quantity of tubing comprise the selective sealing means.
 18. A method for introducing a flowable sealant into a tire from a pressurizable container, comprising the steps of: introducing compressed gas into the container to provide a motive force for a quantity of sealant in the container; and delivering the sealant into the tire through an outlet tube and through a valve stem of the tire while directing a flow of the compressed gas from the container into the outlet tube in association with the flow of the sealant from the container.
 19. The method of claim 18 wherein the sealant is delivered into the tire through a tire valve stem having a core that is not removed from the valve stem during delivery of the sealant. 